Optimizing Spectral Acquisition (Dad Only) - Agilent Technologies 1100 Series Reference Manual

2 How to optmize the Detector

Optimizing Spectral Acquisition (DAD only)

Storage of all spectra consumes a lot of disk space. It is very useful to have all
spectra available during optimization of a method or when analyzing unique
samples. However when running many samples of the same type, the large size
of data files with all spectra may become a burden. The detector provides
functions to reduce the amount of data, yet retaining the relevant spectral
information.
Options for storing spectra
None
Apex
Apex + baseline
Apex + slope +baseline
All in peak
Every 2nd spectrum
All
Range
Only the wavelength range where the compounds in your sample absorb
contains information that is useful for purity checks and library searches.
Reducing the spectrum storage range saves disk space.
Step
Most substances have broad absorbance bands. Display of spectra, peak purity
and library search works best if a spectrum contains 5 to 10 data points per
width of the absorbance bands. For anisic acid (the example used before) a
step of 4 nm would be sufficient. However a step of 2 nm gives a better display
of the spectrum.
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Store signals only. No peak purity checks nor library search
features can be used for samples analyzed with this setting.
Only one spectrum per peak is stored; a peak must be higher than
the value entered in Threshold (see below).
Stores spectra for peaks > threshold at the top and at baseline
before and after each peak recommended minimum to do library
searches with baseline corrected spectra.
Add spectra at the up and down slope; required to do a minimum
peak purity check.
All spectra during all peak > Threshold are stored; required for a
full peak purity check.
Only every second spectrum is stored, occupying only half the disk
space.
All spectra are stored.
1100 Series DAD and MWD Reference Manual